Method and device for changing saw groups of a circular saw

Abstract

The invention relates to a method and a device for changing saw groups (1) of a circular saw (2), in particular a double-spindle circular saw. First of all, replacement saw groups (1) are taken from a magazine (26) and clamped onto clamping mandrels (6a, 6b) of a pivotable head (5a, 5b) that are arranged on the same side of the pivotable head (5a, 5b), after which the pivotable head (5a, 5b) approaches the saw groups (1) to be changed, receives them with the free clamping mandrels (6a, 6b) of the opposite side of the pivotable head and secures them with clamping jaws (7), the saw groups (1) to be changed are released using rotary tools (9) and removed from the circular saw (2) by the pivotable head (5a, 5b) and, after an appropriate safety clearance from the circular saw (2) has been produced, the pivotable head (5a, 5b) is rotated through 180° and the replacement saw groups (1) are fitted onto the circular saw and secured using the rotary tools (9) and the clamping jaws (7) are released before the exchanged saw groups (1) are transferred to the magazine (26) by the pivotable head (5a, 5b).

Description

[0001] Method and device for changing a circular saw

[0002] Technical area

[0003] The invention relates to a method and a device for changing saw groups of a circular saw, in particular a double-spindle circular saw, which comprise circular saw blades clamped on saw bushes.

[0004] State of the art

[0005] The use of double-spindle circular saws has become established in recent decades in the field of sawing technology for processing round and squared timber. Devices of this type are known, for example, from DE 40 38 129 A and EP 0 785 051 A. The main advantages of this technology are a cutting surface with the best surface properties, precise cutting edge retention, and very high cutting performance. The circular saw itself is designed as a group saw, meaning it can perform multiple cuts simultaneously with several saw blades arranged on a common tool, enabling particularly high volume outputs to be achieved with relatively simple machines.

[0006] Due to the circular saw blades and their maximum practical diameter, double-spindle circular saws have a limited cutting height for technical reasons. This is why the cutting process is also carried out from two opposite sides, with two saw assemblies, with the saw blades always working in pairs in a common cutting plane. The material to be cut is pushed through the double-spindle circular saw between the saw spindle axes using a suitable conveyor drive. Furthermore, the two saw assemblies are arranged offset in the cutting direction, ensuring a vertical overlap of several millimeters between the centrifugal circles of the circular saw blades operating in the same cutting plane, ensuring a clean cut through the lumber. This overlap, free of lateral offset, is a prerequisite for a flat surface of the sawn material.

[0007] To ensure this, the radial distance between the saw spindles of the saw groups must be adjustable, depending on the circular saw blade diameter, and must be movable into a wide-open maintenance position. Furthermore, they must be height-adjustable for horizontal spindles and laterally adjustable for vertical spindles, so that the different total cutting heights can be equally divided between both saw groups. To avoid lateral offset, the position of the saw spindles is adjustable in the direction of the saw spindle axis.

[0008] In order to create a twin-spindle circular saw that allows clean cutting within tight tolerances while being compact and enabling quick and easy saw tool changes, it has already been proposed (AT 521963 A4) to have the saw tool mounted overhung on the saw spindle. Saw bushings are releasably attached to the saw spindle via a quick-change cone, which has a corresponding counterpart in the form of a conical stub axle, and are secured in the assembled position with a screw connection coaxial with the saw spindle axis. A head, a screw head, or a screw nut of a screw connection is freely rotatable but axially secured in the tool clamp to actuate the screw connection. This means that the tool clamp can not only be advantageously secured to the saw spindle, but can also be removed from the saw spindle, as the screw connection also acts as a removal tool.Because such a saw group is quite heavy, changing it using muscle power is time-consuming and carries a risk of injury. Specifically, replacing worn saw groups or converting to a differently sized saw group currently takes at least 15 minutes. With downtime costs for industrial circular saw or chipper lines currently approaching €30,000 per hour and more, the savings potential here becomes clear. Illustration of the invention.

[0009] The invention is therefore based on the object of creating a device for changing saw groups of a circular saw that enables rapid and safe changing of the circular saw groups. In particular, a fully autonomous changeover process should be possible without any human intervention and in a fraction of the time required for a manual change.

[0010] A method according to the invention for changing saw groups of a circular saw, namely a double-spindle circular saw, which comprises circular saw blades clamped on saw bushings, solves this problem by first taking replacement saw groups from a magazine and clamping them onto clamping mandrels of a reversible head, which are arranged on the same side of the reversible head, after which the reversible head approaches the saw groups of the circular saw to be changed, in particular those that have been moved apart from one another into a maintenance position, picks them up with the free clamping mandrels of the opposite side of the reversible head and secures them with the clamping jaws, releases the saw groups to be changed with the turning tools and pulls them off the circular saw with the reversible head and, after establishing an appropriate safety distance from the circular saw, rotates the reversible head by 180° and mounts the replacement saw groups on the circular saw, secures them with the turning tools and releases the clamping jaws,before the replaced saw groups are transferred to a magazine with the turning head.

[0011] The lateral offset of the two turning heads can be compensated after removing the changing saw groups and before fitting the replacement saw groups by moving them mutually along a sliding guide transverse to the clamping mandrel axes.

[0012] A magazine having saw bushing receptacles can be displaceable, in particular transversely to the transport axis of the transport carrier, along a magazine guide with a displacement drive between a transfer position close to the circular saw and a storage position, in particular in a sharpening room, in which corresponding maintenance or setup work can be carried out.

[0013] A device according to the invention solves the stated problem by means of two clamping domes projecting in opposite directions from a turning head with clamping jaws that can be radially displaced between a release position and a clamping position, wherein a turning tool that is coaxial to the clamping dome axis is rotatably mounted in each of the clamping domes, the tool holders of which are arranged on the head side of the clamping domes.

[0014] The present invention allows for a fully automatic, rapid, and safe change of saw groups. By providing two clamping domes projecting in opposite directions from a reversible head, it is possible to access the saw group to be replaced using just one spare saw group. The reversible head thus accommodates the spare saw group on one side and the saw group to be replaced on the other. After removing the saw group to be replaced and rotating the reversible head, the replacement tool can be mounted directly on the circular saw. For mounting the saw group on a saw spindle of a circular saw, a tool clamp known from AT 521963 A4 is provided.The tool clamp is detachably attached to the saw spindle via a quick-change cone, which has a corresponding counterpart in the form of a conical axle stub, and is secured in the assembled position with a screw connection coaxial with the saw spindle axis. The screw connection is arranged in a cylindrical recess in the saw bushing opposite the cone. This cylindrical recess serves to accommodate an associated clamping mandrel, which is inserted into the recess to manipulate the saw group with the pivoting head. When the clamping mandrel is properly inserted into this recess, the saw group is secured to the pivoting head with the clamping jaws displaced radially outwards into the clamping position. The clamping jaws are thus positioned on the inside against the saw bushing to radially clamp the saw group. This is preferably done hydraulically, but can also be done mechanically or electromechanically.The saw bush clamping device can be clamped and released using the turning tools mounted in the clamping mandrels coaxially to the clamping dome axis, namely with their tool holders arranged on the head side of the clamping domes.

[0015] For compact design conditions, a common rotary drive can be assigned to the turning tools. In particular, this means that a common rotary drive can be assigned to the two turning tools that protrude from a turning head in opposite directions and penetrate the respective clamping mandrel. This allows the two turning tools to be arranged on a common shaft or rigidly coupled to each other, whereby both turning tools rotate when the rotary drive is actuated, eliminating the need for separate couplings or similar devices.

[0016] In order for the rotary drive to be able to deliver a correspondingly high torque, it is possible to provide a planetary gear in the drive train between the turning tools and the common rotary drive, for example an electric motor or a hydraulic motor, if necessary, and for the rotary drive to be arranged in the turning head.

[0017] The device according to the invention can be used to advantageously change overhung saw groups of any circular saw. If both saw groups of a double-spindle circular saw are to be changed in a single operation, two turning heads can be provided, in particular an upper and a lower turning head, whose clamping mandrel axes are arranged parallel to one another, wherein both turning heads can be displaced with one another transversely to the clamping mandrel axes via a displacement guide with a displacement drive. This allows the offset of the two circular saw axes in the cutting direction and thus the offset of the two turning heads after a 180° rotation to be compensated for by mutual movement along the displacement guide with a suitable displacement drive. This is necessary because the turning heads can each accommodate two saw groups, i.e. a total of four saw groups simultaneously.The displacement guide is preferably assigned a position detection system for mutual displacement. For advantageous rotation, it is proposed that the turning head or heads be mounted on a guide bracket via a turning drive with a turning axis running transversely to the clamping mandrel axes and, if necessary, transversely to the displacement axis of the displacement drive. Depending on the cutting direction, the rotation axis of the turning head can be vertical or horizontal.

[0018] The console can be assigned to any manipulator or robot. However, particularly robust and simple design conditions are achieved when the console is movable along a transport carrier with a transport drive between a saw bush assembly position on the circular saw and a saw bush storage position of the clamping mandrels on a magazine. In particular, the turning head(s) can be suspended from the console, which can be moved accordingly. This transport guide is preferably also assigned a position detection system for the console position.

[0019] If a magazine is assigned to the saw bush storage position, which has saw bush receptacles and which can be moved transversely to the transport axis of the transport carrier along a magazine guide, saw groups can be moved close to the circular saw for a change and, during operation of the circular saw, transported into a so-called sharpening room in which the corresponding maintenance or setup work can be carried out.

[0020] Brief description of the invention

[0021] The drawing shows an example of the subject matter of the invention.

[0022] Fig. 1 a device for changing saw groups of a circular saw in a view obliquely from below,

[0023] Fig. 2 shows a turning head with clamping domes and turning tool in longitudinal section, Fig. 3 shows a clamping dome inserted into a saw group in partially cut longitudinal section and Fig. 4 shows the device from Fig. 3 with the saw group removed from the saw spindle.

[0024] Ways to implement the invention

[0025] The device according to the invention for changing saw groups 1 of a circular saw 2, in particular a double-spindle circular saw, which comprise circular saw blades 4 clamped on saw bushings 3, is characterized by two clamping mandrels 6a, 6b projecting in opposite directions from a reversible head 5a, 5b, with clamping jaws 7 radially displaceable between a release position and a clamping position. A turning tool 9 coaxial with the clamping mandrel axis 8 is rotatably mounted in each of the clamping mandrels 6a, 6b, the tool holders 10 of which, in this case, are hexagon sockets, arranged on the head side of the clamping mandrels 6a, 6b. The radial adjustment of the clamping jaws 7 is preferably effected hydraulically or pneumatically via a pressure medium line I.

[0026] Saw groups 1 are cantilevered on a saw spindle 11. In a double-spindle circular saw, the saw groups 2 are arranged parallel to the saw spindle axes and with the same aligned saw spindle housing 12 in a machine frame or the like (not shown in detail). In order to ensure a change of saw groups 2 or an adaptation of the saw spindle axis distances to different dimensions of saw groups 2, it is necessary for the saw spindles 11 of the saw groups 2 to be adjustable at least in their radial distance a from one another, depending on the circular saw blade diameter, so that the different total cutting heights can be divided equally between both saw groups.

[0027] The sawing tool comprises at least one saw blade, in particular a plurality of circular saw blades 4, namely the circular saw blade group, which is interchangeably mounted on a saw bushing 3 acting as a tool clamp. The saw bushing 3 is releasably attached to the saw spindle 11, which has a corresponding counterpart in the form of a conical spindle stub 15, via a quick-change cone 14 in the manner of a steep taper (for example, 7 / 24), and is secured in the assembled position with a screw connection 16 coaxial with the saw spindle axis. In the exemplary embodiment, the spindle stub 15 is a transition piece mounted on the end of the saw spindle, but can also be formed directly from the saw spindle 11.

[0028] A head 17, a screw head or, as in the exemplary embodiment, a central screw nut, is freely rotatable but axially secured in the saw bushing 3 for actuating the screw connection with a turning tool 9. For this purpose, the head 17 is equipped with a shoulder 18 which, on the one hand, rests against the saw bushing 3 when the screw connection is tightened and, on the other hand, is supported on an annular disk 19 which is axially secured with respect to the saw bushing 3 when the screw connection is loosened and the saw bushing 3 is pulled off the axle stub 15. In this exemplary embodiment, the screw bolt of the screw connection remains on the axle stub 15 when the head is loosened. Likewise, the head can be part of a screw which can be screwed into a thread of the axle stub 15.

[0029] The turning tools 9 can be assigned a common rotary drive 20, which is preferably arranged in the turning head 5a, 5b and comprises an electric motor and / or a hydraulic motor, which is preferably drive-connected to the turning tools 9 via a planetary gear. The two turning tools 9 can be arranged on a common shaft or rigidly coupled to one another (Fig. 2), whereby both turning tools rotate when the rotary drive is actuated and no separate couplings or the like need to be provided. In the exemplary embodiment, each of the two turning tools 9 of a turning head 5a, 5b is rotatably mounted in the associated clamping mandrel 6a, 6b and coupled to the rotary drive.

[0030] Two turning heads 5a, 5b can be provided, the clamping dome axes 8 of which are arranged parallel to one another, wherein both turning heads 5a, 5b can be displaced with one another via a displacement guide 22 with a displacement drive (not shown in detail) transversely to the clamping dome axes 8 in the direction V. The turning head 5a, 5b, here an upper turning head 5a and a lower turning head 5b, is / are rotatably mounted on a guide console 24 via a rotation drive 23 (not shown in detail) with a rotation axis A running transversely to the clamping dome axes 8 and optionally transversely to the displacement direction of the displacement guide 22.

[0031] The guide console 24 can be moved along a transport carrier 25 between a saw bush assembly position near the saw spindles and a saw bush storage position of the clamping mandrels near a magazine 26 using a transport drive (not shown in detail). The magazine assigned to the saw bush storage position has saw bush receptacles 27 and can be displaced transversely to the transport axis of the transport carrier along a magazine guide 28 in the direction L. The saw bush receptacles 27 correspond to a quick-change cone 14 assigned to the magazine 26 for the secure storage of the saw groups 1 on the magazine.

[0032] To change saw groups 1 of a circular saw, in particular a double-spindle circular saw, replacement saw groups are first taken from a magazine 26 and clamped onto clamping mandrels 6a, 6b of the turning head 5a, 5b, which are arranged on the same side of the turning head 5a, 5b. The turning head 5a, 5b then moves the saw groups 1 to be changed, which are moved apart from one another into a maintenance position, with the transport drive along the transport carrier 25, picks up the saw groups 1 of the double-spindle circular saw with the free clamping mandrels 6a, 6b on the opposite side of the turning head, and secures the saw groups 1 with the clamping jaws 7. The saw groups 1 to be changed are then released from the quick-change cones 14 using the turning tools 9 and removed from the double-spindle circular saw using the turning head 5a, 5b.After establishing an appropriate safety distance from the double-spindle circular saw, the turning head 5a, 5b, i.e. both turning heads together, are rotated 180° around the rotation axis A, and the replacement saw assemblies 1 are mounted on the double-spindle circular saw, secured with the turning tools 9 to the quick-change cones 14, and the clamping jaws 7 are released. Finally, the replaced saw assemblies 1 with the turning head 5a, 5b are transferred to the magazine 26.

[0033] The offset of the two turning heads 5a, 5b can be compensated after removing the changing saw groups 1 and before fitting the replacement saw groups 1 by moving them mutually along the sliding guide transversely to the clamping mandrel axis.

[0034] The movable magazine 26 can be frame-shaped and designed such that the part with the saw bushing receptacles 27 can be rotated around a horizontal axis in the center between the saw bushing receptacle pairs arranged one above the other in the drawing in the plane of the table until it reaches a horizontal position. The circular saw blade can be changed, particularly in the sharpening area, with the saw bushing axes vertically aligned. This is advantageous in order to prevent the play between the saw bushing and the circular saw blade bore from becoming one-sided, thus avoiding a significant imbalance of the entire tool, with all the associated negative consequences.

Claims

Patent claims 1. Method for changing saw groups (1) of a circular saw (2), in particular a double-spindle circular saw, which comprise circular saw blades (4) clamped on saw bushings (3), characterized in that firstly replacement saw groups (1) are taken from a magazine (26) and clamped onto clamping mandrels (6a, 6b) of a turning head (5a, 5b) which are arranged on the same side of the turning head (5a, 5b), after which the turning head (5a, 5b) approaches the saw groups (1) to be changed, in particular those which are displaced apart from one another into a maintenance position, picks them up with the free clamping mandrels (6a, 6b) of the opposite turning head side and secures them with clamping jaws (7), releases the saw groups (1) to be changed with turning tools (9) and pulls them off the circular saw (2) with the turning head (5a, 5b) and after establishing an appropriate safety distance from the circular saw (2) rotates the reversible head (5a, 5b) by 180° and pulls the replacement saw groups (1) onto the circular saw,with the turning tools (9) and releases the clamping jaws (7) before the replaced saw groups (1) with the turning head (5a, 5b) are transferred to the magazine (26).

2. Method according to claim 1, characterized in that the offset of two turning heads (5a, 5b) after removal of the saw groups (1) to be changed and before mounting of the replacement saw groups (1) is compensated by mutual movement along a displacement guide (22) transverse to the clamping mandrel axes (8).

3. Method according to claim 1 or 2, characterized in that the magazine having saw bushing receptacles (27) can be displaced along a magazine guide (30) with a displacement drive between a transfer position near the circular saw (2) and a storage position, in particular in a sharpening room.

4. Device for changing saw groups (1) of a circular saw (2), in particular a double-spindle circular saw, which are mounted on saw bushes (3) clamped circular saw blades (4), characterized by two clamping domes (6a, 6b) projecting in opposite directions from a turning head (5a, 5b) with clamping jaws (7) which can be radially displaced between a release position and a clamping position, wherein in each of the clamping domes (6a, 6b) a turning tool (9) which is coaxial with the clamping dome axis (8) is rotatably mounted, the tool holders (10) of which are arranged on the head side of the clamping domes (6a, 6b).

5. Device according to claim 4, characterized in that a common rotary drive (20) is assigned to the turning tools (9).

6. Device according to claim 5, characterized in that the rotary drive (20) is arranged in the turning head (5a, 5b) and comprises an electric motor which is preferably drive-connected to the turning tools (9) via a planetary gear.

7. Device according to one of claims 4 to 6, characterized by two turning heads (5a, 5b), the clamping dome axes (8) of which are arranged parallel to one another, wherein both turning heads (5a, 5b) can be displaced with one another via a displacement guide (22) with a displacement drive transversely to the clamping dome axes (8).

8. Device according to one of claims 4 to 7, characterized in that the turning head (5a, 5b) or that the turning heads (5a, 5b) are rotatably mounted on a guide bracket (24) via a turning drive (23) with a turning axis (A) running transversely to the clamping mandrel axes (8) and optionally transversely to the direction of displacement of the displacement guide (22).

9. Device according to claim 8, characterized in that the guide console (24) is movable with a transport drive along a transport carrier (25) between a saw bush mounting position and a saw bush storage position of the clamping domes (6a, 6b).

10. Device according to claim 9, characterized in that the saw bush storage position is assigned a magazine (26) which has saw bush receptacles (27) and which is displaceable, in particular transversely to the transport axis of the transport carrier, along a magazine guide.

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